As a semiconductor module, a power converter such as an inverter has been known (see Patent Literature 1). In the semiconductor module used for the power converter, a transistor chip as an upper arm switch in the inverter and a transistor chip as a lower arm switch are mounted to be connected together in series on a substrate. The transistor chip includes a vertical transistor chip having a gate electrode pad (control electrode pad) and a source electrode pad (first main electrode pad) on a front surface and having a drain electrode pad (second main electrode pad) on a back surface (for example, Patent Literature 2).